The present invention generally relates to a communication equipment and more particularly, to an automatic on-hook arrangement for a telephone set having a speaker-phone function, without requiring a handset.
Conventionally, in the telephone set of the kind as referred to above, it has been a common practice to establish an off-hook state for communication and an on-hook state for termination of communication through depression of a push button switch, and there are cases where the pushbutton switch remains undepressed carelessly even after termination of the communication, thus resulting in that the telephone set is undesirably left in the off-hook state for communication. Particularly, in the case of a speech recognition telephone, there may be a case where the state for communication is not terminated even when it is intended to complete the communication by uttering a voice for instructing the termination of the communication, e.g. "on-hook", and thus, the telephone set tends to be left in the off-hook state for communication. In this case, if the person at the other end of the line hooks on the telephone set, a warning sound is transmitted from the telephone exchange to the telephone set in the off-hook state for communication, and thus, such telephone set is never left in the off-hook state. However, in the case where the other party is not a person, but a machine as in a weather forecast or correction-time indication, the telephone set at the other party remains in the off-hook state, and thus, the telephone sets at the both ends are left in the off-hook state. Moreover, there has also been such a problem as wrong dialing due to an erroneous recognition arising from noise inputs, etc.